For simplicity, I am defining Taiwan as the main island not any of the outer islands.

Landfall:

The intersection of the surface center of a tropical cyclone with a coastline. Because the strongest winds in a tropical cyclone are not located precisely at the center, it is possible for a cyclone's strongest winds to be experienced over land even if landfall does not occur. Similarly, it is possible for a tropical cyclone to make landfall and have its strongest winds remain over the water.

https://www.nhc.noaa.gov/aboutgloss.shtml#LANDFALL